If you see a dark mass similar to a blown-up balloon at the top of a volcano, what type of feature are you most likely viewing

Working with si (metric) units for each of the following commonly used measurements, indicate its symbol. liter gram milliliter kilogram meter centigram milligram centimeter kilometer second millimeter milliseconds

C3h8o3 - glycerol major species present when dissolved in water

Which is a chemical property of iron? a. it forms iron oxide (rust) when exposed to moisture and air. b. it is a gray–black metal that is hard to the touch. c. it has a melting point of 2795°f (1536°c). d. it is a good conductor of heat